drivers/usb/typec/port-mapper.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB Type-C Connector Class Port Mapping Utility
   4  *
   5  * Copyright (C) 2021, Intel Corporation
   6  * Author: Heikki Krogerus <[email protected]>
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/component.h>
  11
  12 #include "class.h"
  13
  14 static int typec_aggregate_bind(struct device *dev)
  15 {
  16         return component_bind_all(dev, NULL);
  17 }
  18
  19 static void typec_aggregate_unbind(struct device *dev)
  20 {
  21         component_unbind_all(dev, NULL);
  22 }
  23
  24 static const struct component_master_ops typec_aggregate_ops = {
  25         .bind = typec_aggregate_bind,
  26         .unbind = typec_aggregate_unbind,
  27 };
  28
  29 struct each_port_arg {
  30         struct typec_port *port;
  31         struct component_match *match;
  32 };
  33
  34 static int typec_port_compare(struct device *dev, void *fwnode)
  35 {
  36         return device_match_fwnode(dev, fwnode);
  37 }
  38
  39 static int typec_port_match(struct device *dev, void *data)
  40 {
  41         struct acpi_device *adev = to_acpi_device(dev);
  42         struct each_port_arg *arg = data;
  43         struct acpi_device *con_adev;
  44
  45         con_adev = ACPI_COMPANION(&arg->port->dev);
  46         if (con_adev == adev)
  47                 return 0;
  48
  49         if (con_adev->pld_crc == adev->pld_crc)
  50                 component_match_add(&arg->port->dev, &arg->match, typec_port_compare,
  51                                     acpi_fwnode_handle(adev));
  52         return 0;
  53 }
  54
  55 int typec_link_ports(struct typec_port *con)
  56 {
  57         struct each_port_arg arg = { .port = con, .match = NULL };
  58
  59         if (!has_acpi_companion(&con->dev))
  60                 return 0;
  61
  62         acpi_bus_for_each_dev(typec_port_match, &arg);
  63         if (!arg.match)
  64                 return 0;
  65
  66         /*
  67          * REVISIT: Now each connector can have only a single component master.
  68          * So far only the USB ports connected to the USB Type-C connector share
  69          * the _PLD with it, but if there one day is something else (like maybe
  70          * the DisplayPort ACPI device object) that also shares the _PLD with
  71          * the connector, every one of those needs to have its own component
  72          * master, because each different type of component needs to be bind to
  73          * the connector independently of the other components. That requires
  74          * improvements to the component framework. Right now you can only have
  75          * one master per device.
  76          */
  77         return component_master_add_with_match(&con->dev, &typec_aggregate_ops, arg.match);
  78 }
  79
  80 void typec_unlink_ports(struct typec_port *con)
  81 {
  82         if (has_acpi_companion(&con->dev))
  83                 component_master_del(&con->dev, &typec_aggregate_ops);
  84 }